Crossbar

What is Crossbar?

The top (horizontal) bar of the hockey net that sits 4 feet off
the ice and is 6 feet in length.

Sporting Charts explains Crossbar

If a puck hits the two outside metal bars of the net, it's
often said, "The puck hit the post." However, if a puck strikes the
top bar, "The puck hit the crossbar."

The crossbar is also used when a player bats the puck out of the
air and into the net, to determine if the goal was legally batted
in. A player must keep the stick below the crossbar when directing
or deflecting a puck into the net.

The league continues to tinker with ideas to tweak the goal nets
by either making them bigger, or even curving the crossbar to
possibly increase scoring.